Lubricants and preparation thereof



Patented Aug. 28, 1945 OFFICE LUBRICAN TS AND PREPARATION THEREOF Eugene Lieber, West'New Y., and Caleb E. Ho signors, by mesne as Brighton, Staten Island, dges, Elizabeth, N. 3., assignments, to Standard Catalytic Company, a corporation of Delaware No Drawing. Application December-'31, 1942,

' Serial No. 470,820 I 5 Claims.

This invention relates tonovel lubricants and to methods of preparing same, and more particularly to the improvement of lubricants which contain small amounts of wax, and to which have been added small amounts or pour depressors to facilitate the flowing of such lubricants at low temperatures- It has been known for some years thatwaxy mineral lubricating oil having, for instance a pour point of about +30 F. can be made to pour quite freely at temperatures considerably below 0 F. if a smallamount, such as about 0.1% to 1% of a substance called a pour depressor, 'is dissolved in the waxy lubricating oil. Such a pour depressor which has been available commercially for a number of years is one made by condensing a chlorinated paraffin wax containing about 10 to 15% chlorine with naphthalene in the presence of aluminum chloride catalyst, with subsequent hydrolysis and removal of the catalyst and distillation of the condensation product under reduced pressure to an elevated temperature, such as about 600 F. to obtain the desired pour depressor as distillation residue.

Although the exact mechanism of the pourdepressing phenomenon is not known with certainty, it is believed that the pour depressor does not actually prevent the development of wax crystals, but merely prevents the growth of such wax crystals into long needle-like forms, th'ereby preventing the development of a mesh-like structure of such needles, which is believed primarily responsible forthe refusal of the oil to pour. However, it has sometimes been observed that when waxy lubricating oil containing a, pour depressor is maintained at a temperature at or near the cloud point of the oil itself, waxy constituents separate out from the oil, either as a cloud in the oil or as a more or less flocculent or crystalline precipitate. This is most apt to occur in certain types of oils. such as neutral and distillate, to which pour depressprs have been added.

It is an object of the present invention to suppress the growth or separation of such wax particles from pour depressor-treated oils, either by reducing, delaying or preventingsuch growth or separation.

Broadly, the invention comprises adding to a pour depressor-treated oil a small amount of a wax suppressor, the amount required being in the range of from about .05% to about 1.5%, preferably between the limits of about 0.2% and 1.0%, the most effective quantity of wax suppressor varying with the exact type of suppressor used and also with the quantity and nature of wax in the lubricating oil based on the total weight of oil.

The wax supressor may be an organic ester of an inorganic acid, such as boric acid. Such esters may be considered as having the general formula RBOa, in which R represents an organic radical, preferably a hydrocarbon radical, such as alkyl, aryl, naphthenyl, or mixed hydrocarbon radical. As typical examples of the esters of boric acid which can be used, the following may be cited by way of illustration:

Amyl borate Butyl borate Octadecyl borate Oleyl borate Phenyl borate Di-amyl phenyl borate Tertiary amyl phenyl sulfide borate Naphthyl borate Naphthenyl borate (from petroleum naphthenic acids) Similar esters of silicic acid may be used. Other classes of materials which have been found useful as' wax suppressors include the following: high molecular weight alcohols, such as octadecyl alcoh'ol, high molecular weight ketones, such as hepta decyl phenone and metallic naphthenates.

The objects, advantages and mechanism of the invention will be better'understood from the following example.

A blended lubricant was made up of the follow--v ing composition:

Percent Manchester spindle oil 98.5 Pour depressor 1 L0 Butyl borate 0.5

Pour depressor of the Paraflow condensation ance of the stored oil samples as to whether or not particles of wax were discernable.

It was found that the sample not containing any butyl borate yielded a heavy precipitate of solid wax particles after 6 days of storage, whereas the sample containing 0.5% of butyl borate required 32 days for wax sedimentation to appear. It is thus clear that the butyl borate has a powerful effect in suppressing the growth of wax particles or in retarding the separation 01 wax particles from a waxy mineral lubricating oil containing a pour depressor.

It is interesting to note that the butyl borate itself has only a slight efiect on the pour point of the Manchester spindle oil, since it reduced the pour point only from +30 F. to +15 FL, when used in 0.5% concentration. Itwas also found that the butyl borate did not alter the pour point of the blend of pour depressor in the Man chester spindle oil, because 1% of Paraflow reduced the pour point of the spindle oil from +30 F. to -l5 FL, and yet a blend of spindle oil containing 1% of Paraflow in addition to 0.5% of but-yl -borate had exactly the same pour point, namely F.

For the sake of convenience the experimental data discussed above in connection with this example are summarized in the following table:

Per cent composition P Dayst gg our point crys a s i- Test Bum (ASTM) F. mentation Oil P. D.1 g at+ F 99 1 -l5 s 98.5 1 0.5 -15 32 99.5 -e o. 5 +15 1 Pour depressor oi the Iaraflow type.

Thus the butyl borate apparently does not affeet the pour point itself to any great extent, but its only efiect is to act as a wax suppressor, in preventing the formation of or separation of solid wax particles from a pour depressor-treated oil when such an oil is stored for a substantial period of time at a temperature in the vicinity of the cloud point of the oil.

. given merely for the sake of illustration, nor unnecessarily by any theory as to the mechanism of the operation of the invention, but only by the appended claims in which it is intended to claim all novelty inherent in the invention, as well as all modifications coming within the scope and spirit of the invention.

We claim:

1. Composition comprising a waxy hydrocarbon oil, a small but pour depressing amount of a pour depressor comprising essentially a Friedel- Crafts condensation product of chlorinated wax and naphthalene and a small but wax suppressing amount of a wax suppressor comprising essentially an organic ester of an inorganic acid selected from the group consisting of boric acid and silicic acid.

1 2. Composition according to claim 1 in which the wax suppressor is an organic ester of boric acid.

of a pour depressor comprising essentially a- Friedel-Crafts condensation product of chlorinated wax and naphthalene, and about .05-1.5% of butyl borate.

EUGENE LIEBER. CALEB E, HODGES. 

